Conventionally, in a case where a driving circuit such as a gate driver is constituted by using transistors Tr101 and Tr102 of an identical conductivity type as illustrated in FIG. 15, interconnection between the transistor Tr101 and the transistor Tr102 is made via a source metal (SE) (see FIG. 16(b)). Alternatively, in a case where a power source and/or other element(s) which are placed by using the SE lie between the transistor Tr101 and the transistor Tr102, interconnection between the transistor Tr101 and the transistor Tr102 is made via the SE or a gate metal (GE) (see FIG. 16(a)). Note that in FIGS. 16(a) and 16(b), regions marked with dashed lines indicates a silicon layer, regions marked with solid lines indicate the gate layer which is provided on the silicon layer, and regions filled with a color of gray indicate the metal layer which is provided on the gate layer.